[mpohio]

I purchased the Sig 556 rifle after I had gotten my 556 pistol. Mostly because of the $300 rebate, but also cause I loved the pistol so much. It took some time to find the right ammo for it. Finally after 4 trips and serval different types, I found the 75gr rounds work the best with the 1in7 twist barrels. Especially the Hornady tap 75gr precision( see last pic). The Cheaper prvi 75 grain had better groups on my previous target, but didn't have any pics.

So the only two 75 gr bullets really out grouped the 55gr by far. The good news is I finally got some great groups. The bad news is the damn ammo cost a small fortune!! Prvi=$13, Hornady=$15 per 20rnds. It really sucks as my Bushmaster Predator loves the $6 PMC "bronze" stuff. Of course its 1in8 twist. I wish Sig would have used a 1in8 twist for us Civilians.




50yds 3 shot groups. Sig556 w/ Leop vx1 3-9. Wind was Left to Right at 5 mphs and temp was 60 f

 

[ddnuts]

Very nice shooting and thanks for the info.

 

[moses]

Does the 75 gr hornady ammo have a crimp on the bullet?

Nice group!

 

[SkyPup]

My SIGs handle the 75's much better than the 62's or 55's for sure. Even the 69 grainers seems to work much better. Both my rifles are zeroed in on the 75's.

 

[moses]

My Sig 556 shoots my reloads with 24 grs of Varget and the 55 gr hornady bullets better than any other load. It will shoot the 75 gr Hornady bullets almost as well with the 69 gr Seirra match kings a close third but those are both two times more expensive than the 55 gr.

 

[mpohio]

Does the 75 gr hornady ammo have a crimp on the bullet?

Nice group!

Not sure what you mean by a crimp. I just looked at one and they are smooth all over. I found them at a local gun store in vandalia ohio. They were $15.99 a box of 20 :shock: I tried to find them on the net for cheaper but keep coming up with a different one.

the box says Hornady TAP : 223 REM, 75gr Precision #80265 (if that helps)

Except for my Mini 14s all my barrels have been 1in8 twists. This is the first 1in7 so I was getting real frustated at the accuracy, until I bought some 75gr ammo. The higher the twist the lower the gr you should use is a good general rule of thumb. 1in8 is good middle of the road twist that shoots about anything well. IE my BUshmaster predator.

I hope to get back to the range, weather permitting, later this week to test it out at 100yds. That will be the true test. I really want to find some cheap sub $9 75gr but that is easier said than done.

Here is a great site to find cheap ammo:
http://www.ammoengine.com/find/ammo/.22 ... _5.56x45mm

 

[nycstripes]

Good information. Might just be some hope left for my rifle as well with the heavier bullets.

 

[sigdizzy]

i can't group within 6 inches with 55 gr pmc in my 1/7 twist, hornady 75 gr is sub moa all day long....swiss barrel

 

[mpohio]

I was about to sell mine as the groups sucked butt. I did find out the following from our range master today:

1in7 twist great for heavier loads mostly military and larger game
1in8 good middle of the road that pretty much is good with all grains.
1in9 good for lighter grain 55 and smaller loads. small varmit and paper gun

I don't think sig did to much research behind their civilian version. It would have been better received if it had a 1in8, as most of us use the cheaper 55gr. I myself love the PMC "bronze" 55gr. My Bushmaster predator is a frickin tac driver with it. and its like $6 a box!!

 

[sigdizzy]

I think Sig did pile of research on the 1/10 twist and even developed a specific 63 gr (Ruag GP 90) ammo for it, which is very accurate, used the 1/7 twist in their shorter barrels for cqb and heavier bullets and that is what the U.S. market ended up getting. Didn't set out to cater to U.S. market just went with what they had. Glad you found the right ammo and are enjoying your rifle....now. They truly are wonderful to shoot. Every time I shoot mine, its like shooting it for the first time and brings smiles.....mind you that may just be aged and lack of memory.